Sterilization of reusable and delicate, precision surgical instruments and their subsequent sterile storage is of paramount concern to surgeons and hospitals. Sterilized surgical instruments are essential during surgical procedures to minimize the risk of infection.
After sterilization, airborne bacteria may enter sterilization containers through vents and apertures and, if coming in contact with a suitable medium, may incubate to harmful levels. Condensation remaining after sterilization, either in the tray or on the instruments, provides such a medium for the growth of deleterious bacteria during the subsequent storage of the sterilized instruments.
Some example prior art patents which provide for sterilization containers are Arp et al U.S. Pat. No. 4,643,303, Nichols U.S. Pat. No. 4,728,504, and Spence U.S. Pat. No. 4,783,321. These prior art patents generally teach the use of baskets or trays to hold the instruments to be sterilized, and apertures in the baskets which allow for gross drainage of condensation from the baskets to the container floor below the basket. The condensation then must again drain from the container floor. This double drainage increases the risk of condensation remaining in proximity to the sterilized instruments and the subsequent contamination of the condensation by airborne bacteria. These prior art baskets or instrument retention devices are of such design that excessive condensation may be trapped between the instruments and the device.
Many prior art patents have no separate container locking device to provide a sealing effect between the container halves. Thus the flow of steam or other gaseous sterilants during sterilization is not firmly restricted to the apertures. More importantly, air may ingress between the container halves after sterilization, thus increasing the risk of airborne bacterial contamination of any remaining condensation.
U.S. Pat. No. 4,643,303 describes a sterilization container enclosing an instrument basket within a box-like base and cover. The container also includes clamps mounted to the container by hinges for releasably holding the cover to the base. U.S. Pat. No. 4,783,321 describes a sterilization container enclosing an instrument basket within a base and cover. The container also includes a latch mechanism for releasably holding the cover to the base.
Most of the prior art, for example Nichols U.S. Pat. No. 4,728,504, provide for the placement of the instruments on a removable basket or tray which includes apertures formed on the bottom of the tray to allow for the drainage of condensation. The domed configuration of the tray bottom in U.S. Pat. No. 4,728,504 allows for sufficient surface area contact with the instruments such that condensate may be held between the instruments and the tray after sterilization. Such a risk of airborne bacterial contamination of remaining condensation after sterilization increases during increased storage of the sterilized instruments. Thus, it is imperative to remove as much condensation as possible from the container and from the instruments after sterilization.
Hauze, U.S. Pat. No. 4,798,292, describes a non-locking sterilization container with apertures arranged in rows and columns enclosing a flat surfaced insert with apertures arranged in rows and columns such that the apertures in the container and the insert are vertically aligned. Pegs are inserted in the insert apertures to provide horizontal separation of the instruments during sterilization and subsequent presentation of the instruments. The flat surface of the insert and the pegs increase the risk of condensation remaining in proximity to the instruments after sterilization.
This prior art, although providing for condensation drainage, does not sufficiently alleviate the risk of condensation bacterial growth. Condensation may be trapped between the instruments and the excess support surfaces, and condensation may not sufficiently drain from the container due to convoluted drain paths.
It is an object of the present invention to provide a sterilization and storage container tray and mat which substantially reduce the risk of remaining condensation during storage of the instruments.
It is a further object of the present invention to provide a tray surface which provides minimal contact with the instruments to allow for condensation drainage away from the instruments.
It is also an object of the present invention to provide a tray which allows for condensation drainage away from the bottom of the tray.
SUMMARY OF THE INVENTION
It has now been discovered that the objects of the present invention can be accomplished in the following manner. Specifically, an improved sterilization and storage container tray has been discovered which is admirably suitable for minimizing condensation accumulation within the container tray and thus decreasing the risk of condensation bacterial growth.
The container tray consists of two locking tray halves enclosing a mat made of rubber, plastic or other synthetic material suitable for use in sterilization. The mat may be either stiff or flexible, although in the preferred embodiment the mat is made of flexible silicone rubber and is treated to have a low coefficient of friction. The mat includes upwardly tapering finger-like projections on its upper surface upon which the instruments rest. This tapering reduces the total surface contact area between the instruments and the mat and, combined with the low coefficient of friction of the mat, facilitates the gravity drainage of condensation. This smaller total surface contact area also reduces the risk of condensation being trapped between the instrument and the mat.
The mat also has apertures formed on the bottom of the mat through which the condensation drains. The bottom tray base has apertures which correspond to, and are vertically aligned with, the mat apertures so that condensation draining from a mat aperture may pass freely through the corresponding base aperture directly beneath it.
Raised projections are formed on the bottom of the mat to space the mat from the tray bottom so as to further facilitate condensation drainage away from the mat and instruments, thus decreasing the risk of remaining condensation.